Conventionally, as a technology for objectively measuring the refraction data of an eye, correction factors such as S (spherical power), C (astigmatic power), and A (angle of an astigmatic axis) are measured by the use of a refractometer. In recent years, eye-characteristics measurement apparatuses capable of measuring even higher-order aberration have been developed, and therefore, correction factors such as S, C, and A on a line such as a ring having a diameter of 3 mm used by a refractometer can be calculated from lower-order aberration. When such an eye-characteristics measurement apparatus is used, values closer to subjective values than those obtained by a refractometer are obtained especially for sick eyes and eyes on which refractive-power-correction operations have been performed. The following documents, for example, should be referenced.
Japanese Patent Application No. 2001-119145
Japanese Patent Application No. 2001-120002
Japanese Patent Application No. 2001-119086
Japanese Patent Application No. 2000-318534